Human growth hormone (hGH) is an important therapeutic being produced at high cost by recombinant methods. The Phase I of this SBIR has demonstrated the feasibility of producing this hormone in the milk of transgenic mice. The present aim is to produce hGH in the milk of transgenic rabbits which are easy and economical to handle. Transgenic rabbits will be screened for hGH expression in their milk samples. Rabbits producing high levels of the hormone will be propagated. Methods will be devised to maximize milk yield and purify hGH in large amounts. Accomplishment of the neurons unknown challenges will give us a clear understanding of the feasibility of using animals as bioreactors to produce other important therapeutics in a least expensive manner.